COROT, due for launch in late 2006, will be the first spacecraft devoted to the search
for rocky planets, similar to our own Earth. It will look for the tiny drop in light caused by a planet as it slips across the face of its parent star.

COROT is a CNES mission with ESA participation.

Credits: CNES/D.Ducros

26 October 2006
The COROT space telescope is proceeding smoothly towards its launch in December 2006. Once in orbit, COROT will become the first spacecraft devoted to the search for rocky planets, similar to our own Earth.

COROT will also delve into the centres of hundreds or even thousands of stars.

COROT will lead a bold new search for planets around other stars. In the decade since the discovery of the first exoplanet, 51 Pegasi b in 1995, more than 200 other planets have been detected from ground-based observatories. COROT promises to find many more during its two-and-a-half-year mission, and to expand the frontiers of our knowledge toward ever smaller planets. It will look for the tiny drop in light caused by a planet as it slips across the face of its parent star.

Most of the planets COROT will detect are expected to be 'hot-Jupiters'. Each hot Jupiter is a large gas giant planet in close orbit around its central star. An unknown percentage of the planets detected by COROT are expected to be rocky worlds, maybe just a few times larger than the Earth (or even smaller). If COROT finds these worlds, they will represent a new class of planet. "COROT will provide the first mapping of rocky planets around other stars," says Malcolm Fridlund, ESA’s Project Scientist for COROT.

This artist’s impression shows the surface of a possible exo-
planet placed at exactly the right distance from its parent star
for liquid water to exist on its surface.

COROT, due for launch in late 2006, will be the first spacecraft
devoted to the search for rocky planets similar to our own Earth.
Of all the rocky worlds, this space telescope will be most
sensitive to detect those closer to their parent star than Mercury
is to the Sun.

Credits: ESA. Illustration by Medialab

Artist's view of a rocky, Earth-like exoplanet
Of the rocky worlds, COROT is most sensitive to those with orbits of 50 days or less. That would place them closer to their parent star than Mercury is to the Sun. In most cases, such proximity to a star would scorch them beyond habitability. However, if such a world were discovered around a red dwarf star, it could be placed at exactly the right distance for liquid water to exist on its surface.

Led by the French national space agency, CNES, COROT is a mission of international collaboration: other partners are Austria, Spain, Germany, Belgium and Brazil. ESA plays a crucial role in the mission. Its Research and Scientific Support Department designed, built and tested COROT's two on-board data processing units. In addition, ESA provided the optics for the telescope, which sits at the heart of the spacecraft.

Photo of the COROT's telescope primary mirror, manufactured by SAGEM/REOSC.

Credits: Sagem

ESA also tested the telescope at its ESTEC facilities in The Netherlands. The telescope itself contains a primary mirror of 30 centimetres in diameter. During the mission, it will collect the light from thousands of stars and feed it into a special two-part camera.

One half of the camera is designed to look for planets; the other half is optimised to detect the subtle variation in a star’s light, caused by sound waves rippling across the surface. These waves are the equivalent of seismic waves on the Earth.

By studying them, astronomers can gain a detailed insight into the internal conditions of the star. The technique is known as asteroseismology. ESA’s Solar and Heliospheric Observatory (SOHO) has been pioneering similar investigations of the Sun for many years. It has proved to be an extremely successful way to probe the internal conditions of a star and astronomers are eager to extend the technique to other stars.

COROT will target at least fifty specific stars for a detailed study in this way. By choosing stars of different sizes and behaviour, COROT will supply astronomers with the most complete picture of stellar evolution to date. "Stellar physics is not a 'done deal'. In fact, we are really just beginning with it," says Fridlund.

COROT stands for 'Convection Rotation and planetary Transits'. The name describes the scientific goals of the mission with convection and rotation referring to the asteroseismology. Both goals require the camera to be sensitive to changes in a star's light of just one part in one hundred thousand. To help reach this sensitivity, a design team at ESA came up with a highly successful baffle that traps any stray light from entering the telescope.

To further help the accuracy of the COROT data, ESA plan to use its ground station on Tenerife to make follow-up observations. For 30 nights during the next year, its telescope there will target the regions of sky that COROT studies. It will look for contaminating sources of light and variable stars that might fool the COROT observations.

The launch of COROT opens an exciting new chapter in the quest for planets around other stars. "ESA has been working for a long time towards the detection of Earth-like worlds around other stars. COROT is an important first step in this direction and helps to pave the way for ESA's future flagship mission, Darwin, dedicated to the direct detection of Earth-like worlds and their atmospheres to search for signs of life." says Sergio Volonte, Head of the Science Planning and Community Coordination Office at ESA.

Artist’s view of COROT, the exoplanet hunter mission led by CNES,
with ESA participation. Due for launch at the end of 2006, COROT
will be placed on a circular, polar orbit around Earth that will allow
for continuous observations of two large and opposite regions in the
sky for more than 150 days each.

Within each region there are many selected fields that will be monitored in turn. The reason for the oppositely sited regions is that, because of the Earth’s movement around the Sun, the sun’s rays start to interfere with the observations after 150 days. COROT then rotates by 180 degrees and start observing the other region.

Credits: CNES/D.Ducross

14 November 2006
The launch of COROT on 21 December 2006 is a long awaited event in the quest to find planets beyond our Solar System. Searching from above the Earth's atmosphere, COROT – the CNES project with ESA participation - will be the first space mission specifically dedicated to the search for extrasolar planets.

COROT is expected to greatly enlarge the number of known exoplanets during its two-year mission and provide the first detection of rocky planets, perhaps just a few times the mass of the Earth.

Artist's impression of exoplanets around other stars

Credits: ESA 2003. Illustration by AOES Medialab.

"COROT could detect so many planets of this new type, together with plenty of the old type that astronomers will be able to make statistical studies of them," says Malcolm Fridlund, ESA's Project Scientist for COROT.

This will allow astronomers to more accurately predict the number and type of planets that will be found around other stars.

The world of astronomy changed forever on 6 October 1995, when Michel Mayor and Didier Queloz of the Geneva Observatory announced the first discovery of a planet around a star similar to the Sun. As well as celebration, there was surprise because 51 Pegasi b, as the planet became known, was half the mass of Jupiter and orbiting much closer to its parent star than expected. Whereas Mercury orbits the Sun at 57.9 million kilometres in 88 days, 51 Pegasi b shoots around its orbit in just 4.23 days. This indicated that the planet was just 7.8 million kilometres from its star.

This illustration shows a newly discovered Jupiter-like planet and its hypothetical moon
(the blue orb) circling the star 55 Cancri. A previously known large planet is just to the
left of the star and a hypothetical Earth-like planet to the right of the star.

Credits: ESA/Lynette Cook

An American team led by Geoff Marcy, San Francisco State University, and Paul Butler, University of California, Berkeley, soon discovered other planets around other stars. They too were large, Jupiter-like planets in extremely close orbits.

These planets had not been seen directly. Instead, their presence had been inferred by the gravitational pull they exerted on their parent star. The astronomers had measured the wobble of the star through changes in its light, and used this data to calculate the orbit and minimum mass of the planet.

COROT relies on a new way of detecting planets. As tens of thousands of people witnessed on 8 June 2004, a planet moving across the face of the star creates a noticeable silhouette. On that day, onlookers watched the black dot of Venus slip across the Sun’s bright surface.

COROT is designed to detect such transits of extrasolar planets across the faces of their parent stars. It will monitor the brightness of stars, looking for the slight drop in light caused by the passage of the planet. Because this relies on the chance alignment of the star and the planet with Earth, a large number of stars must be monitored to make certain of seeing enough events. COROT will monitor hundreds of thousands of stars. "The first target field is towards the galactic centre. Then the spacecraft will turn towards Orion," says Fridlund.

COROT will be the first extrasolar planet search mission capable of seeing the smaller, rocky worlds; although they will have to be in close orbits around their stars. COROT also opens the way for the future. Two years later, in October 2008, NASA will launch Kepler, a space telescope with a 0.95 metre mirror. Kepler works the same way as COROT, looking for planetary transits, and is expected to find the first Earth-sized planets in similar orbits to our world.

Following Kepler, a new technique will be needed. The problem is that the larger the telescope's mirror, the smaller its field of view becomes. So building a larger telescope to reach fainter stars means restricting the area of sky it looks at. Although seeing fainter stars brings gains, the field of view shrinks, leaving fewer stars in total available.

Claude Catala, Observatoire de Paris-Meudon, amongst others has proposed a method that may solve this problem. Instead of a larger space telescope with a smaller field of view, the new proposal uses hundreds of 10-cm telescopes in parallel.

Each telescope is smaller than most amateur astronomers use on Earth but each has a wide field of view, 30 degrees across. That’s about 60 times the width of the full Moon. Because they are so small, each tiny telescope is incapable of collecting enough light on its own to make a useable image. However, a computer on the proposed spacecraft would combine the faint images recorded by each tiny telescope. This would give enough information to detect transits. Thus, the future of detecting planetary transits may be to launch a spacecraft that contains hundreds of mini-telescopes.

After this, the next big leap in planetary searches is likely to be the isolation of reflected light from a planet. This would allow the planet’s atmosphere to be chemically analysed. In the case of an Earth-like world, the analysis could reveal signs of life. ESA is currently developing the necessary technology to make such a mission possible. They are developing it under the name of Darwin, to be possibly launched after 2020.

16 November 2006
The COROT satellite, designed to detect exoplanets and study the interiors of stars, safely reached the Baikonur cosmodrome in Kazakhstan on board an Antonov 124 cargo plane on 15 November 2006, and it is now being prepared for launch.

COROT, a CNES mission with ESA participation, will be sent into Earth orbit by a Soyuz rocket on 21 December 2006. CNES in collaboration with Alcatel - who built the satellite - have just kicked-off COROT's 5-week launch campaign. In parallel, those responsible for ground and science operations are rehearsing the procedures by which the satellite will be placed and operate in its orbit and by which its instruments will start working once in space.

After being removed from its container, COROT will be tested to check possible damage due to transportation. After this, its fuel tanks will be filled with hydrazine, which will power its attitude-control system once in orbit. Finally, further tests will verify the correct positioning of the satellite’s multi-layer insulation sheets, to ensure proper thermal protection in space.

Waspie_Dwarf 8,904

Opening of the COROT shipping container in Baikonur (Kazakhstan) on 17 November 2006.

Credits: CNES/René Perez

4 December 2006
The COROT satellite has completed an important step in its 5-week launch campaign after fuelling up for its almost 3-year mission. Launch is currently scheduled for 21 December from the Baikonur cosmodrome, in Kazakhstan.

Following its arrival 15 November at the Baikonur Cosmodrome, COROT was immediately transferred to the MIK 112 integration and test building, where it will remain until shortly before launch.

Here, the satellite has undergone a series of functional clean-room tests to check that it is unscathed after its journey, which it made in a particularly comfortable 15-tonne Spacebus 4000 pressurized container, from Alcatel Alenia Space's Telecoms product line.

Although more than wide enough for COROT, the oversized container was needed to accommodate the satellite's sunshield, which is more than 4 metres long.

A long pit stop

Spacebus 4000 pressurized container.

Credits: Credits: CNES 2006 (Laurent Trebosc et Laurent Boisnard)

The satellite's tanks were full by Wednesday 29 November, after 9 days of fuelling operations. Although COROT is only carrying 40 litres of hydrazine fuel, "hydrazine is highly poisonous, so the surrounding area has to be scrupulously secured and great care must be taken to ensure tanks and fuelling lines are completely tight," explains the mission's System Manager Laurent Boisnard, CNES.

If the launch, currently scheduled for 21 December, were to be postponed for any reason, COROT's tanks can remain fully fuelled until a new launch date is set.

Paving the way for future Europe-Russian cooperation

Snowy launch pad in Baikonur on 28 November 2006.

Credits: CNES/René Perez

If COROT cannot leave on 21 December, the launch will be rescheduled for the next day at the same time minus 3 minutes 56 seconds to allow for the lag between the sidereal day — the time taken for the Baikonur Cosmodrome to be in the same position relative to the stars — and the solar day, which is the time taken for Earth to complete a full revolution with respect to the Sun.

COROT will launch atop a Soyuz 2-1B, a variant developed specially for future Soyuz launches from the Guiana Space Centre in Kourou. The generic Soyuz 2-1A has already made two successful flights, the most recent having orbited the MetOp-A satellite on 19 October 2006.

COROT's launch will be the first flight for the new third-stage RD-124 full-flow engine, which recently completed a comprehensive series of ground qualification tests.

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thebarman 6

If I could ask a question from someone who knows more about this than me, can you tell me how astronomers can accurately calculate the size of exo-planets from the shadow they make across their neighbouring star?

Using my rather rudementary diagram below, (not to scale, obviously) as I see it because of our perspective from Earth an exo-planet could be larger and closer to its star or smaller and further away but appear the same size to us.

Please forgive any ignorance I may have shown, I am merely curious as to how they do this and appreciate any answer

The light from the star will drop as the planet passes in front of the star. By measuring the percentage drop in the light relieved from the star you can calculate the percentage of the stars disk that was obscured.

The next thing you need to know is how far the planet is away from the star. This is done by simple orbital mechanics. The time that the planet takes to cross the face of the star is measured. If the diameter of the star is known you will be able to calculate the speed at which the planet is orbiting the star. From this the distance from the star to the planet can be calculated.

Once you know the distance from the star to the planet and the relative size of the planet compared to the star then it is possible to calculate the planet's actual size.

Of course this will not be 100% accurate as there will be limits to the accuracy and precision of the measurements (which will vary from object to object) but it will still give a fairly accurate estimate.

7 December 2006
COROT, the upcoming mission to detect exoplanets and probe the interior of stars, is now scheduled for launch on 27 December 2006 from the Baikonur cosmodrome in Kazakhstan.

The launch, previously planned for 21 December, had to be postponed due to a leak detected in the fuel circuit of the Soyuz launcher's upper stage (Fregat).

After launch, COROT will be set onto a polar circular orbit around Earth. This orbit will allow for continuous observation of two large regions in opposite directions of the sky for more than 150 days each. Within each region there are many selected star fields that will be monitored in turn. The first target field is towards Orion, then the spacecraft will turn towards the centre of our Galaxy, the Milky Way.

This artist's view shows the COROT satellite, consisting of a 30-centimetre space
telescope to be launched in late 2006.

COROT will use its telescope to monitor closely the changes in a star’s brightness that
comes from a planet crossing in front of it.

While it is looking at a star, COROT will also be able to detect ‘starquakes’, acoustical
waves generated deep inside a star that send ripples across a star’s surface, altering
its brightness. The exact nature of the ripples allows astronomers to calculate the star's
precise mass, age and chemical composition.

Credits: CNES 2006 - D. Ducros

19 December 2006
ESA PR 47-2006. On 27 December, COROT is to be launched into space on a unique astronomy mission: its twin goals are to detect exoplanets orbiting around other stars and to probe the mysteries of stellar interiors as never before. COROT is a French national space agency (CNES)-led mission to which the European Space Agency and European partners are adding a particularly strong international flavour.

While CNES is completing preparations for the launch from Baikonur/Kazakhstan, ESA and a large number of European scientists involved in the mission are eagerly awaiting this event and the first scientific results to come through.

What is COROT?

COROT stands for ‘Convection Rotation and planetary Transits’. The name describes the mission’s scientific goals. ‘Convection and rotation’ refer to the satellite’s capability to probe stellar interiors, studying the acoustic waves that ripple across the surface of stars, a technique called asteroseismology. ‘Transit’ refers to the technique whereby the presence of a planet orbiting a star can be inferred from the dimming starlight caused when the planet passes in front of it. To achieve its twin scientific objectives, COROT will monitor some 120,000 stars with its 30-centimetre telescope.

One of the methods for detecting exoplanets is to look for the drop in brightness they
cause when they pass in front of their parent star. Such a celestial alignment is known
as a planetary transit.

From Earth, both Mercury and Venus occasionally pass across the front of the Sun.
When they do, they look like tiny black dots passing across the bright surface.

Such transits block a tiny fraction of the light, that the COROT mission will be able
to detect.

Credits: CNES

COROT will lead a bold new search for planets around other stars. In the decade since the first discovery in 1995 of an exoplanet (51 Pegasi b ), more than 200 other such planets outside our solar system have been detected using ground-based observatories. The COROT space telescope promises to find many more during its two-and-a-half-year mission, expanding the frontiers of our knowledge towards ever-smaller planets.

Many of the planets COROT will detect are expected to be 'hot Jupiters', gaseous worlds. An unknown percentage of those detected are expected to be rocky planets, maybe just a few times larger than the Earth (or smaller, even). If COROT finds such planets, they will constitute a new class of planet altogether.

When looking at stars, COROT will be able to detect ‘starquakes’, acoustical waves
generated deep inside a star that send ripples across a star’s surface, altering its brightness.
The exact nature of the ripples allows astronomers to calculate the star's precise mass, age
and chemical composition.

This technique is known as asteroseismology and ESA’s Solar and Heliospheric Observatory
(SOHO) has been taking similar observations of the Sun for years.

Credits: CNES

While it is looking at a star, COROT will also be able to detect 'starquakes', acoustic waves generated deep inside a star that send ripples across its surface, altering its brightness. The exact nature of the ripples allows astronomers to calculate the star's precise mass, age and chemical composition.

COROT’s European dimension

The COROT mission was first proposed by CNES back in 1996. A call for potential European partners was issued in 1999. CNES gave the green light to build the spacecraft in 2000 and is now leading the mission. Its international partners are ESA, Austria, Belgium, Germany, Spain and Brazil.

CNES is responsible for the overall system and for the launch contract with Franco-Russian company Starsem, which is providing the Soyuz launch service.

The contributions of the other international partners range from the provision of hardware items to ground stations, complementary ground-based observation of targets to be studied by COROT and analysis of the scientific data to come.

Photo of the COROT's telescope being prepared for a 'first-light' test on ground.

Credits: CNES

ESA is playing a crucial role in the mission. It has contributed the optics for the telescope positioned at the heart of the spacecraft and has carried out payload testing. The telescope’s baffle was developed by a team at ESA’s technical centre ESTEC. ESA has also provided the onboard data processing units. And under this truly collaborative effort, a number of scientists from various European countries - Denmark, Switzerland, the United Kingdom and Portugal - have been selected as Co-Investigators following open competition. As a result of ESA’s participation, scientists from its Member States will also be given access to COROT data.

Arianespace's launcher family in action: Corot is readied for its Soyuz mission with Starsem

Arianespace will complete its 2006 launch activity with a December 27 flight that utilizes a Soyuz ST vehicle to orbit the European Corot astronomy satellite.

The Corot payload was booked by Arianespace specifically to be orbited by Soyuz ST, underscoring the company's mission flexibility with its growing family of launch vehicles. Our photo report from Baikonur Cosmodrome in Kazakhstan details the final preparations for this mission, which is being performed with the expertise of Arianespace's Starsem affiliate (click on the images for a larger version):

Corot is prepared for its fueling in Starsem's Hazardous Processing Facility at Baikonur Cosmodrome. Built by Alcatel Alenia Space, the Corot satellite will spend approximately three years studying the vibratory performance of stars to determine their internal structure, age and composition. It also will seek out new planets, possibly confirming the existence of telluric celestial bodies with physical properties comparable to the solar system's own rocky planets.

Following its transfer to the Starsem Upper Composite Integration Facility, Corot is ready to be installed on the Fregat upper stage, which is visible in the background. The re-ignitable Fregat propulsion system will make two burns during the mission to place Corot in a circular polar orbit. Separation of the satellite from its upper stage will occur 50 minutes after liftoff.

With Corot in the horizontal position, the satellite is ready for its encapsulation in the payload fairing (at left). The 626-kg. satellite is based on the CNES-developed Proteus multi-mission bus, and carries a focal telescope to measure variations in the intensity of observed light sources. International participants in the Corot program include France, Austria, Spain, Germany, Brazil and the European Space Agency.

Soyuz is transferred to the launch pad for its December 27 liftoff with COROT

Preparations for the December 27 Soyuz mission with Europe's COROT astronomy satellite have entered their final phase at Baikonur Cosmodrome in Kazakhstan.

The Soyuz 2-1b is shown on launch pad no. 6 at

Baikonur Cosmodrome.

The Soyuz vehicle rolled out from its final integration facility on Sunday, December 24, and was erected on the Cosmodrome's launch pad no. 6.

This flight is being conducted under the joint responsibility of Arianespace and its Starsem affiliate – which performs commercial operations with the Soyuz launcher. The COROT payload was booked by Arianespace specifically to be orbited by Soyuz, underscoring the company's mission flexibility with its growing family of launch vehicles.

The December 27 mission uses an upgraded Soyuz 2-1b version of the workhorse Russian-built launcher, which features improved navigation accuracy, enhanced control capability and a more powerful third stage engine. It represents the latest step in the cooperative European/Russian program to evolve Soyuz, which subsequently will be introduced by Arianespace in commercial operations from the Spaceport in French Guiana.

With Soyuz' future service start-up at the Spaceport, it will become the reference medium-class launch vehicle for governmental and commercial missions, joining the heavy-lift Ariane 5 and lightweight Vega.

The COROT payload for tomorrow's Soyuz launch was developed by the French CNES national space agency in an international scientific effort involving France, Austria, Spain, Germany, Brazil and the European Space Agency. The 605-kg. satellite was produced by Alcatel Alenia Space, and is designed to study the vibratory performance of stars to determine their internal structure, age and composition.

Data from the spacecraft also will be used to seek out new planets, possibly confirming the existence of telluric celestial bodies with physical properties comparable to the Solar System's own rocky planets.

This artist's view shows the COROT satellite, consisting of a 30-centimetre space
telescope to be launched in late 2006.

COROT will use its telescope to monitor closely the changes in a star’s brightness that
comes from a planet crossing in front of it.

While it is looking at a star, COROT will also be able to detect ‘starquakes’, acoustical
waves generated deep inside a star that send ripples across a star’s surface, altering
its brightness. The exact nature of the ripples allows astronomers to calculate the star's
precise mass, age and chemical composition.

Credits: CNES 2006 - D. Ducros

27 December 2006
Launched today from Kazakhstan, the unique astronomy mission COROT is on its way. Its twin goals are to detect exoplanets orbiting around other stars and to probe the mysteries of stellar interiors as never before. COROT is a French national space agency (CNES)-led mission to which ESA and European partners are adding a particularly strong international flavour.

COROT was launched by a Soyuz-Fregat from Baikonur in Kazakhstan at 15:23 CET. Status reports on the mission are available from CNES at: http://www.cnes.fr/corot_en/

What is COROT?

COROT stands for 'Convection Rotation and planetary Transits'. The name describes the mission's scientific goals. 'Convection and rotation' refer to the satellite's capability to probe stellar interiors, studying the acoustic waves that ripple across the surface of stars, a technique called asteroseismology. 'Transit' refers to the technique whereby the presence of a planet orbiting a star can be inferred from the dimming starlight caused when the planet passes in front of it. To achieve its twin scientific objectives, COROT will monitor some 120 000 stars with its 30-centimetre telescope.

COROT will lead a bold new search for planets around other stars. In the decade since the first discovery in 1995 of an exoplanet (51 Pegasi b ), more than 200 other such planets outside our solar system have been detected using ground-based observatories. The COROT space telescope promises to find many more during its two-and-a-half-year mission, expanding the frontiers of our knowledge towards ever-smaller planets.

Many of the planets COROT will detect are expected to be 'hot Jupiters', gaseous worlds. An unknown percentage of those detected are expected to be rocky planets, maybe just a few times larger than the Earth (or smaller, even). If COROT finds such planets, they will constitute a new class of planet altogether.

While it is looking at a star, COROT will also be able to detect 'starquakes', acoustic waves generated deep inside a star that send ripples across its surface, altering its brightness. The exact nature of the ripples allows astronomers to calculate the star's precise mass, age and chemical composition.

COROT's European dimension

The COROT mission was first proposed by CNES back in 1996. A call for potential European partners was issued in 1999. CNES gave the green light to build the spacecraft in 2000 and is now leading the mission. Its international partners are ESA, Austria, Belgium, Germany, Spain and Brazil.

CNES is responsible for the overall system and for the launch contract with Franco-Russian company Starsem, which is providing the Soyuz launch service.

The contributions of the other international partners range from the provision of hardware items to ground stations, complementary ground-based observation of targets to be studied by COROT and analysis of the scientific data to come. ESA is playing a crucial role in the mission. It has contributed the optics for the telescope positioned at the heart of the spacecraft and has carried out payload testing.

The telescope's baffle was developed by a team at ESA's technical centre ESTEC. ESA has also provided the onboard data processing units. And under this truly collaborative effort, a number of scientists from various European countries - Denmark, Switzerland, the United Kingdom and Portugal - have been selected as Co-Investigators following open competition. As a result of ESA’s participation, scientists from its Member States will also be given access to COROT data.

The upgraded Soyuz 2-1b vehicle soared to success on its inaugural flight today, marking a key milestone in the development of Russia's workhorse launcher - while also lofting the European COROT astronomy satellite.

After lifting off from Kazakhstan's Baikonur Cosmodrome at 8:32 p.m., the Soyuz deployed COROT at the completion of a 50-minute mission, placing the 630-kg. satellite into a circular polar orbit. It was the 1,717th flight of a Soyuz vehicle.

The flight was carried out under the joint responsibility of Arianespace and its Starsem affiliate, which performs commercial operations with the Soyuz launcher. COROT was booked by Arianespace in January 2005 specifically to be orbited by Soyuz, demonstrating the company's mission flexibility with its growing family of launch vehicles.

The Soyuz 2-1b vehicle incorporates a more powerful third stage engine, representing the latest step in a cooperative European/Russian program to evolve Soyuz - which subsequently will be introduced by Arianespace in commercial operations from Europe's Spaceport in French Guiana.

Today's Soyuz 2-1b mission builds on the successful introduction of the improved Soyuz 2-1a launcher, which has flown three times. The initial Soyuz 2-1a flight occurred in November 2004 from Russia's Plesetsk Cosmodrome, and was followed by Starsem's utilization of the vehicle to orbit the MetOp-A meteorological satellite last October from Baikonur Cosmodrome. Another Soyuz 2-1a mission was performed several days ago, when a Russian governmental payload was launched from Plesetsk Cosmodrome on December 24.

Improved flight control and increased performance

The Soyuz 2-1a version implements a digital control system that gives increased mission flexibility and also provides additional flight control authority required when the new, enlarged Soyuz ST fairing is installed on the vehicle. These improvements are carried over to the Soyuz 2-1b, which is further enhanced with its increased-performance third stage engine.

When the improved Soyuz enters service at the Spaceport, this launcher will become the reference medium-class vehicle for governmental and commercial missions - joining the proven heavy-lift Ariane 5 that already is in service, as well as the lightweight Vega, which currently is advancing through its development phase.

Arianespace CEO Jean-Yves Le Gall, who also is Chairman & CEO of Starsem, said COROT's successful orbiting demonstrates the benefits of the companies' launcher family approach. "With Ariane 5 and Soyuz, we have marked one of our best operational years," he explained. "The five Ariane 5 missions and two Soyuz launches we performed in 2006 orbited no less than 12 satellites."

The COROT payload lofted by Soyuz 2-1b today was developed by the French CNES national space agency, which organized an international scientific effort involving France, Austria, Spain, Germany, Brazil and the European Space Agency. Produced by Alcatel Alenia Space, COROT is a pioneering satellite designed to study the vibratory performance of stars to determine their internal structure, age and composition. Data from the spacecraft also will be used to seek out new planets, possibly confirming the existence of telluric celestial bodies with physical properties comparable to the Solar System's own rocky planets.

In the night between 17 and 18 January 2007, the protective cover of the COROT
telescope has been successfully opened, and COROT has seen for the first time light
coming from stars.

The first light detected by 30-centimetre COROT telescope comes from the
constellation of the Unicorn near Orion, the great ‘hunter’ whose imposing
silhouette stands out in the winter nights.

Credits: CNES

24 January 2007
In the night between 17 and 18 January 2007, the protective cover of the COROT telescope has been successfully opened, and COROT has seen for the first time light coming from stars.

Surveying vast stellar fields to learn about star interiors and to search for extra-solar planets is the goal of this unique mission, whose scientific observations will officially start at the beginning of February this year.

The first light detected by COROT comes from the constellation of the Unicorn near Orion, the great 'hunter' whose imposing silhouette stands out in the winter nights. This nice image, taken during the in-orbit calibration exercise, shows that the quality of this preliminary data is basically as good as the computer simulations. "This is an excellent piece of news," commented Malcolm Fridlund, ESA Project Scientist for COROT.

After its launch in December 2006, COROT will be placed by a Soyuz launcher in a
polar circular orbit around Earth at an altitude of 896 kilometres.

This orbit that will allow for continuous observations of two large and opposite regions
in the sky for more than 150 days each.

The reason for the oppositely sited regions is that, because of the Earth’s movement
around the Sun, the sun’s rays start to interfere with the observations after 150 days.
COROT then rotates by 180 degrees and start observing the other region.

Credits: CNES

On 18 January, the telescope was carefully aligned with the region to be observed, facing away from the centre of our Galaxy. This setting that will be maintained until April, when the Sun's rays will start to interfere with the observations.

COROT will then rotate by 180 degrees and will start observing the opposite region towards the centre of the Milky Way. In the meantime the COROT scientists are preparing for the science phase to start in February, continuing a thorough examination of the data and the information collected so far.

Note

COROT was successfully launched on a Souyz rocket from the Baikonur cosmodrome,
Kazakhstan, on 27 December 2006.

Credits: CNES/Starsem

COROT was set in space by a Soyuz rocket after a text-book launch from the Baikonur cosmodrome in Kazakhstan on 27 December 2006. Settled in its almost-circular polar orbit ranging between 895 and 906 kilometres altitude over the Earth's surface, the spacecraft was powered on 2 January 2007, and has begun its calibration exercise, still on going.

Major steps of this testing phase have been the test of the COROT four thrusters's nozzles, necessary to precisely orient the spacecraft in space, and the calibration of the light sensors. The sensor calibration process, which paradoxally must take place in total darkness, is designed to check the detector arrays pixel by pixel. For a given amount of light, a pixel doesn't generate exactly the same amount of current as its neighbours, so these individual responses must be taken into account when applying corrections to the scientific data to come.

COROT is a CNES project with ESA participation. The other major partners in this mission are Austria, Belgium, Brazil, Germany and Spain.

This artist's view shows the COROT satellite, consisting of a 30-centimetre space
telescope launched on 27 December 2006.

COROT will use its telescope to monitor closely the changes in a star’s brightness that
comes from a planet crossing in front of it.

While it is looking at a star, COROT will also be able to detect ‘starquakes’, acoustical
waves generated deep inside a star that send ripples across a star’s surface, altering
its brightness. The exact nature of the ripples allows astronomers to calculate the star's
precise mass, age and chemical composition.

Credits: CNES/D. Ducros

5 February 2007
One month after successful launch, and about two weeks after the release of the first image of the sky, the COROT satellite successfully entered in 'fine pointing' mode.

The fine-pointing configuration was uploaded on 24 January 2007 after the activation of the seismology channel, and uses the satellite telescope as a 'super' star sensor. This will allow COROT to precisely target stars and perform astero-seismologic observations (probing stars interiors).

The optical performances of the seismology channel prove to be excellent, both in terms of shape and stability of the image spots, with a distortion incredibly close to the on-ground modelling performed before launch.

In late January 2007, inside the images collected to calibrate the seismology channel,
COROT detected a junk object - a piece of a Delta 1 rocket launched in 1984.

This has left on the COROT's camera sensors (CCD) a small smear visible in the middle
of this stellar field image. The movement of the object inside the CCD image fits well
with the trajectory elements computed on ground.

Credits: CNES

Inside the images collected to calibrate the seismology channel, COROT detected a junk object - a piece of a Delta 1 rocket launched in 1984. This has left on the COROT's camera sensors (CCD) a small smear visible in the middle of the stellar field. The movement of the object inside the CCD image fits well with the trajectory elements computed on ground.

These and all the delicate operations of verification and in-orbit calibration of the COROT satellite – also including a program of calibrations relative to the instrument line of sight performed from 18 to 23 January - have been mastered by the satellite teams at CNRS (Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique (Observatoire Paris Meudon) and at Laboratoire d'Astrophysique de Marseille (Observatoire Astronomique de Marseille Provence).

Three months after launch, CNES’s COROT stellar seismology and exoplanet hunting mission is poised to reach a highly symbolic milestone. In a few days’ time, the project team that has watched over the satellite from its design stage will hand over to controllers tasked with operating it through to the end of the mission.

In the space industry, “in-orbit checkout” is the period of a few months following the launch of a spacecraft during which teams run a series of checks to ensure it is acclimatizing to the rigours of space. This task includes verifying that the spacecraft bus and instruments perform as planned in readiness to accomplish the mission.

COROT completed this phase on 26 March when the project team gave its final report on the satellite’s performance to the review group and mission operations teams set to take over between now and mid-April.

Artist's view of Corot.
Credits : CNES/Ill. D.D Ducros

Exceptional pointing performance

The results of in-orbit checkout are excellent, none more so than the exceptional precision of the fine-pointing mode developed especially for COROT. “We are seeing a precision of 0.25 arc seconds,” enthuses Pierre Bodin, who is in charge of the instrument on the project team. “That’s 2 times better than our initial objective.” To get an idea of just how precise, this means the instrument can resolve features as small as a hair’s breadth from a distance of 90 m.

COROT user guide

“The in-orbit checkout review produces a sort of user guide for the COROT operations team,” explains Pierre Bodin. “So, controllers now have everything they need to meet the mission scientists’ needs without jeopardizing data quality or the satellite’s safety.”

First debriefing by the project team of seven weeks
of commissioning in orbit.
Crédits : CNES/L. Boisnard

Following this ultimate presentation, the review group will submit a certain number of questions to the development teams in the next few days before the final handover.

“The project team’s experts will of course be on hand if needed at any later stage,” says Pierre Bodin.

But he doesn’t expect they will be overly troubled. “The operations teams now have a baby that can walk and has already made good progress. And scientists are really delighted with the data they’ve been receiving since 6 February. Mission accomplished.”

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COROT discovers its first exoplanet and catches scientists by surprise

3 May 2007

This is an artist’s impression of a Jupiter-sized planet passing in front of its parent star.

Such events are called transits. When the planet transits the star, the star’s apparent brightness drops by a few percent for a short period. Through this technique, astronomers can search for planets across the galaxy by measuring periodic changes in a star’s luminosity.

The first class of exoplanets found by this technique are the so-called “hot Jupiters,” which are so close to their stars they complete an orbit within days, or even hours.

Credits: NASA, ESA and G. Baco

COROT has provided its first image of a giant planet orbiting another star and the first bit of ‘seismic’ information on a far away, Sun-like star- with unexpected accuracy.

The unanticipated level of accuracy of this raw data shows that COROT will be able to see rocky planets - perhaps even as small as Earth - and possibly provide an indication of their chemical composition.

COROT, a CNES project with ESA participation, is a mission with a dual goal. It is the first space mission dedicated entirely to the search of extra-solar planets. It provides a wide-field survey of planets like our own at an unprecedented level of accuracy. It is also making the most comprehensive study ever of the interior of stars other than our Sun. Both objectives are achieved by analysing the behaviour of light emitted by a target star.

An exoplanet is detected by COROT due to a sudden decrease in the intensity of light or the ‘light curve’ of a parent star when a planet transits in front of it.

This image shows the signature of the presence of a planet orbiting a star.

The intensity of light coming from the star is represented on the y-axis whereas the x-axis shows the phase, or the revolution of the planet around the star.

The amount of light from the star reaching COROT decreases each time the planet passes in front of the star itself. This is when the drop is registered.

This was the first planet detected by COROT since the beginning of its mission. This light curve is part of a data set obtained between February and April 2007.

The planet is a very hot gas giant, of radius equal to 1.78 times that of Jupiter. The planet takes 1.5 days to revolve around the star.

Coordinated spectroscopic observations from the ground have allowed to determine that the mass of the planet is about 1.3 times that of Jupiter. The parent star is a yellow dwarf star similar to our Sun. It is located in the direction of the constellation Unicorn (Monocerus), roughly 1 500 light years from us.

Credits: COROT exo-team

The study of stellar interiors – or ‘asteroseismology’ – is carried out by analysing the oscillations in the light curve of the star. The oscillations are created due to mechanical waves propagating in the star itself and they give a clue to the structure of its interior.

COROT’s strength lies in the continued observation of the same targets in a given area of the sky. The observations have been on since the science operations began, 60 days ago. Another strong point is the accuracy with which it measures the variations in the luminosity of the star.

The first planet detected by COROT, now named ‘COROT-Exo-1b’, is a very hot gas giant, with a radius equal to 1.78 times that of Jupiter. It orbits a yellow dwarf star similar to our Sun with a period of about 1.5 days. ‘COROT-Exo-1b’ is situated roughly 1500 light years from us, in the direction of the constellation Unicorn (Monoceros). Coordinated spectroscopic observations from the ground have also allowed the determination of the mass of the planet, equivalent to about 1.3 Jupiter masses.

The scientific evaluation of the results that are streaming in will take some time. “The data we are presenting today is still raw but exceptional,” says Malcolm Fridlund, COROT Project Scientist for ESA. “It shows that the on-board systems are working better than expected in some cases - up to ten times the expectation before launch. This will have an enormous impact on the results of the mission.”

As the planet passes in front of its parent star, the brightness of the star decreases.

All the sources of noise and disturbance have not yet been taken into account in the data. This first exoplanet was detected with an error of only five parts out of 100 000 during one hour of observation. When all the corrections are applied to the light curves, the error will be reduced to only one part out of 100 000.

As a consequence, small planets down to the size of our Earth – three times smaller than initially thought possible - will be in the grasp of COROT. The satellite may also be able, in specific circumstances, to detect subtle variations in the stellar light reflected by the planet itself. This would give an indication of its chemical composition.

The quality of the asteroseismological data is equally impressive. Excellent ‘starquake’ data were obtained during the first 60 days of observations, with a margin of error of less than one part per million.

This image shows the light curve emitted by a binary star system as seen by COROT.

The crests show light emitted by both stars. However, when one star eclipses the other, the troughs are created due to a decrease in the amount of light reaching COROT. The periodicity is seen since the stars are revolving around each other with a fixed period.

The light curve was obtained by COROT during observations performed between February and April 2007.

This high quality of this light curve is due to the continuity of the observations and their high accuracy.

Credits: COROT exo-team

COROT observed a bright Sun-like star continuously for 50 days, showing large, unexpected luminosity variations on time scales of a few days. This may be related to the star’s magnetic activity.

The accuracy of these measurements was truly outstanding: with an error of five parts out of 100 000 in one minute (corresponding to one part per million over four minutes), COROT has already reached the maximum performance for a telescope of its size.

The preliminary analysis of the oscillations in stellar luminosity clearly shows the seismic signature typical of a Sun-like star. This analysis will eventually help scientists understand the star’s internal structure and age.

“COROT, a joint endeavour between France, Europe and Brazil under the leadership of CNES, was certainly born under a lucky star,” concluded Fridlund. “After a perfect launch, and a faster-than-expected start of its science operations, we have been eagerly awaiting its data. Now, having seen its quality, we can expect great discoveries in the future.”

Notes

COROT was launched by a Soyuz rocket from the Baikonur cosmodrome in Kazakhstan on 27 December 2006. Settled in its almost-circular polar orbit ranging between 895 and 906 kilometres above the Earth's surface, the spacecraft was powered on on 2 January 2007 and started its science observations on 3 February this year.

COROT is a CNES project with ESA participation. The other major partners in this mission are Austria, Belgium, Brazil, Germany and Spain.

20 December 2007
The space-borne telescope, COROT (Convection, Rotation and planetary Transits), has just completed its first year in orbit. The observatory has brought in surprises after over 300 days of scientific observations.

Pioneering precision measurement over long periods of time COROT is observing a large number of stars, up to 12 000, simultaneously, at a very high precision - unprecedented in ground-based astronomy. The key to the high-precision is that the observations can be carried out over very long periods of time – up to 150 days. This is being done for the first time ever.

The satellite measures variations in the light output of these stars down to one part in a million. This level of precision allows scientists to study the many ways in which stars vary. The pulsations are caused either due to unknown physical processes in the stellar interior, or by objects such as planets passing in front of the stellar surface.

A treasure trove of information for stellar seismology

This figure displays the frequencies of the different modes of oscillations observed by COROT in a star of the Delta Scuti type.

Delta Scuti is a class of variable stars in which the variations found (for example also in the Sun) are exaggerated, and thus are easier to study. Scientists expect to increase their understanding of the mechnaisms causing stellar variability by observing several Delta Scuti stars with COROT.

The different peaks provide information about the internal constituency of the star. The level of detection from the ground is represented by the red horizontal line.

Credits: COROT exo-team

To date, 30 stars have been observed as part of the study of stellar seismology, the study of the miniscule changes in light output from a star caused by acoustic waves travelling through the star. The pattern of the changes tells us a lot about what is happening deep inside the star. The stars observed by COROT range from objects similar to our own Sun to older or more massive stars. The observation period varies between 20 and 150 days of essentially uninterrupted study.

After a preliminary analysis, the measurements have revealed very exciting results

Research into solar-type oscillations is one of the mission’s key objectives. Such oscillations have already been found in two stars that are very similar to our sun - first in HD49933 and then in HD181420. The variations are very weak in amplitude and given their short coherence time (the duration for which a particular wave persists on the stellar surface), they are very hard to detect and measure.

COROT’s discovers its second exoplanet

This is the light-curve of the parent star of COROT-exo-2b.

The observation was carried out for 140 days. The light-curve contains 78 passages of the planet in front of the star. This is a record, compared to previous (ground-based) observations where transits sometimes take place in the daytime and are impossible to observe.

The photometric precision obtained in this light-curve is also without precedence, and remains constant during the whole sequence. It reaches 160 parts per million in an integration time of 2.5 minutes – a value impossible to obtain with any ground-based instrument. The light-curve also contains much information about the star itself. It shows periodic modulations, probably the result of different rotational velocities at different latitudes of the star.

This is another nice example of COROT’s superior performance and demonstrates the impact that this mission will have on our understanding of stellar activity and its connection to extrasolar planets.

Credits: COROT exo-team

As a planet passes in front of a star, there is a dip in the light output from the star, which is detected by COROT. Since many other processes can mimic the signature observed, to confirm the presence of a planet, a large confirmation programme with supplementary ground-based observations is necessary to prove the existence of a planet.

Although COROT observes thousands of light curves, the pace of discovery is governed by ground-based observations.

In the third sequence of COROT observations, a likely time for the transit of COROT-exo-2b in front of its star was worked out and an analysis of the light curve was carried out in real-time to confirm the find. Observations were carried out simultaneously at the observatory of Haute Provence in France, and at the European Southern Observatory in Chile, confirming the existence of the planet and its mass was measured.

COROT-exo-2b orbits a star similar to our Sun, somewhat more massive and cooler, but more active. It is located about 800 light-years from Earth in the direction of the constellation Serpens. COROT-exo-2b is a giant planet, 1.4 times larger and 3.5 times more massive than Jupiter. Its average density of 1.5 grams per cubic centimetre is also somewhat higher than Jupiter’s. This massive planet orbits its star in a little less than two days from a distance of about six times the stellar radius.

"Christmas is early this year,” for ESA's COROT Project Scientist, Malcolm Fridlund. “The release of the first data set has already had the science team working hard. The quality of the data is fantastic and the results will change both, how we see exoplanets and how we understand stars."

Notes:

During the spring of 2007, COROT discovered its first exoplanet, named COROT-exo-1b.

On 10 December 2007, the first set of data obtained by COROT was released to the Co-Investigators of the mission. These scientists hail from the member states of the COROT consortium (ESA, Austria, Belgium, Brazil, Germany, and Spain). The actual analysis of large amounts of data has just begun and is expected to speed-up with the release of the next data segment in February 2008.

In the data obtained, many light curves show signs of exoplanets in transit and are being followed-up from ground. Within this list of objects which is growing by the day, two candidates stand out as particularly interesting. One planet is half the size of Saturn, and another is the size of Jupiter, but with a very unusual density.

The discovery of COROT-exo-1b and COROT-exo-2b is described in three scientific papers that will be submitted to scientific journals in the next few days.

COROT has observed four regions so far:

One zone in the direction of the constellation of the Unicorn (Monoceros) for 60 days

Two regions in the opposite direction on the sky, towards the constellation of the Snake's tail (Serpens Cauda) – one short for 26 days and one long for 150 days.

A new region in the direction of the Unicorn, where COROT will remain for at least 150 days

COROT was launched by a Soyuz rocket from the Baikonour cosmodrome in Kazakhstan on 27 December 2006. Settled in its almost-circular polar orbit ranging between 895 and 906 km above Earth's surface, the spacecraft was powered on 2 January 2007 and started its science observations on 3 February this year.

COROT is a CNES project with ESA participation. The other major partners in this mission are Austria, Belgium, Brazil, Germany and Spain.

This artist's view shows the COROT satellite, consisting of a 30-centimetre space telescope launched on 27 December 2006.

COROT will use its telescope to monitor closely the changes in a star’s brightness that comes from a planet crossing in front of it.

While it is looking at a star, COROT will also be able to detect ‘starquakes’, acoustical waves generated deep inside a star that send ripples across a star’s surface, altering its brightness. The exact nature of the ripples allows astronomers to calculate the star's precise mass, age and chemical composition.

Credits: CNES/D. Ducros

Two new exoplanets and an unknown celestial object are the latest findings of the COROT mission. These discoveries mean that the mission has now found a total of four new exoplanets.

These results were presented this week at the IAU symposium 253 in Massachusetts, USA.

COROT has now been operating for 510 days, and the mission started observations of its sixth star field at the beginning of May this year. During this observation phase, which will last 5 months, the spacecraft will simultaneously observe 12 000 stars.

The two new planets are gas giants of the hot Jupiter type, which orbit very close to their parent star and tend to have extensive atmospheres because heat from the nearby star gives them energy to expand.

“Scientists suspect that with the detection of COROT-exo-3b, they might just have discovered the missing link between stars and planets.”
In addition, an oddity dubbed ‘COROT-exo-3b’ has raised particular interest among astronomers. It appears to be something between a brown dwarf, a sub-stellar object without nuclear fusion at its core but with some stellar characteristics, and a planet. Its radius is too small for it to be a super-planet.

If it is a star, it would be among the smallest ever detected. Follow-up observations from the ground have pinned it at 20 Jupiter massses. This makes it twice as dense as the metal Platinum.

Scientists suspect that with the detection of COROT-exo-3b, they might just have discovered the missing link between stars and planets.

“COROT has also detected extremely faint signals that, if confirmed, could indicate the existence of another exoplanet, as small as 1.7 times Earth’s radius.”

COROT has also detected extremely faint signals that, if confirmed, could indicate the existence of another exoplanet, as small as 1.7 times Earth’s radius.

This is an encouraging sign in the delicate and difficult search for small, rocky exoplanets that COROT has been designed for.

Note:

COROT was launched atop the Soyuz from the Baikonour cosmodrome in Kazakhstan on 27 December 2006. Settled in its almost-circular polar orbit ranging between 895 and 906 km above Earth's surface, the spacecraft was first powered on 2 January 2007 and started its science observations on 3 February of the same year.

COROT is a CNES project with ESA participation. The other major partners in this mission are Austria, Belgium, Brazil, Germany and Spain.